After typing ack 'sub foo' lib for the approximately
thousandth time during some refactoring sessions, I couldn't be bothered
anymore and added the following snippet to my realias
(after some googling on how to get params into an alias, which does not
work in bash, so I had to solve it via a bash function):

sack () { ack "sub $1" lib}

To find a given method in some of our labyrinthine code, I now say

~/projects/Foo-Bar$ sack annoying_method

and get a list of all occurrences.

yay!

P.S.: The name sack has nothing do with subroutine ack, but of course comes from the Austrian
saying "Gemma ned am sack, oida!"